Hollow light-metal girder



l 643 577 Sept. 27, 1927. c. DORNIER l I HOLLOW memmam. emmm Filed April 1925 Fig.

JNVENTUR:

Patented Sept. 27, 1927.

UNITEDASTATES PATENT OFFICE.

CLAUDIUS DORNIEB, OI FBIEDBICHSI IAIEN-ONETEE-BODENSEE, GERMANY, .ASSIGNOB I TO THE FIB-I:- mama, IETALLBAU'IEN GESELLSOHAI'T m IBESCEBKNKTEB ELFTUNG, OI FRIEDBIGESEAI'EN, GERMANY.

HOLLOW LIGHT-METAL GIBDEB.

Application fled April 80, ms, Serial No. 685,4";5, and in Germany August 21, 1938.

My invention relates to hollow light metal beams or girders and more especially to beams or girders formed of two channels combined in such a manner,that theirflanges overlap each other and are fixed to one another by suitable means.

It is an object of my invention to provide .a beam or girder of this type which is stronger than similar members of equal weight.

tion several girders embodying my invention are illustrated diaigliammatically by way of example. In the wings Figure 1 is a cross section of one, and Figure 2 is a similar view of another form. Referring to Figure 1 two channels a and b are combined into a hollow-beam in such manner thattheir flanges overlap'each other in pairs. The webs a and d form the side walls of the hollow girder and are provided with circular apertures e. The flanges are connected by rows of rivets.

While the flanges of channel a are flat, 2 those of channel b are grooved or corrugated longitudinally at g, the grooves or corruga- In the drawings aflixed to this specifications being covered and closed by the flat flanges of the channel a. The rim of each flange of the channel I) is turned inwards at h.

In Figure 2 each flange of channel a has three corrugations i which are covered and closed at the inner side by the flat flanges of channel b, adjoining flanges forming a hollow member which is materially stronger than a combination of flat or corrugated flan of the ordinary type. g

I wish it to be understood that I do not desire to be limited with the exact details of construction and configuration, shown and described, for obvious modifications will 40 occur to a person skilled in the art.

I claim: a

A structural metallic member comprising two light sheet metal channels comblned in such manner that their flanges overlap one another almost entirely, one of two adjoining flanges being corrugated longitudinally, the other one being flat, and means for rlgidly connecting the flanges, v

In testimony whereof I aflix my signature.

' cLA DIUs DORNIER. 

